The prior art discloses a number of solutions by means of which a rotor of a centrifuge can be mounted firmly on a drive shaft. For example, it is known to press the rotor onto a conical seat of a drive shaft by means of a screw thread.
DE 197 21 335 A1 discloses a solution in which a rotor is mounted on the drive shaft by means of a special chuck. This solution is not self-locking and requires a tool for detaching the rotor.
A self-locking solution is disclosed in EP 0 712 667 B1. However, the unlocking mechanism disclosed therein is difficulty available for many conventional designs of rotor, and the rotor is not guided sufficiently without play, which might result in dynamic instability at relatively high loads and rotational speeds.
EP 0 911 080 A1 discloses a system that ensures substantial absence of play and good accessibility to the unlocking mechanism. However, it is only suitable for specific types of rotor that do not generate any forces (for example, buoyancy forces) contrary to the coupling direction.
DE 10 2008 045 556 A1 develops the principle of EP 0 911 080 A1 and explicitly provides for counteracting buoyancy forces up to a force of approximately 100 N. At forces below this value, it is impossible to unlock the rotor from the drive head in the axial direction. However, this system reaches its limits when higher buoyancy forces and/or very high rotational speeds occur. In the case of high buoyancy forces and simultaneous pivoting of the coupling elements or in the case of poorer properties of the friction combination, the self-locking feature of the system is overridden and the rotor can become unlocked from the drive head in the axial direction. Furthermore, the rotor gets jammed as a result of the high centrifugal forces at very high rotational speeds and the coupling cannot always be easily detached.